1. Field of the Invention
The present invention relates generally to devices for generating output optical energy distributions and, more particularly, to lasers.
2. Description of Related Art
A variety of laser systems have existed in the prior art. A solid-state laser system generally comprises a laser rod for emitting coherent light and a stimulation source for stimulating the laser rod to emit the coherent light. Flashlamps are typically used as stimulation sources for laser systems, for example, but diodes may be used as well for the excitation source. The use of diodes for generating light amplification by stimulated emission is discussed in the book Solid-State Laser Engineering, Fourth Extensively Revised and Updated Edition, by Walter Koechner, published in 1996, the contents of which are expressly incorporated herein by reference.
With reference to FIG. 1, a conventional laser assembly 25 may comprise a housing 27 containing a laser module 29, which is connected by way of an optical connector 31 to a trunk fiber 33. The optical connector 31 is typically disposed within and concealed by a portion of the housing 27 and, further, is typically constructed to facilitate attachment and removal of the trunk fiber 33 to and from the housing 27. Moreover, in the illustrated prior-art example, the trunk fiber 33 extends in an uninterrupted fashion from the housing 27 up to and through a handpiece 35. Furthermore, the trunk fiber 33 continues in an uninterrupted fashion from the handpiece 35 through a pre-bent tip cannula 38 and terminates at an energy output end 40 of the trunk fiber 33. The pre-bent tip cannula 38 comprises a rigid plastic or a stainless steel material.
A spool (not shown) can be disposed in close proximity to the optical connector 31, for storing extra trunk fiber 33. The spool can be secured to the housing 27 to provide a user with access and to enable the user to increase a length of the trunk fiber 33 by advancing addition trunk fiber 33 from the spool toward the handpiece 35. In typical implementations, the energy output end 40 of the trunk fiber 33 can exhibit signs of wear or damage after use, and thus should be replaced on a regular and frequent basis. To this end, after each use, the user will typically need to cleave a portion (e.g., between 3 and 10 millimeters) off of the energy output end 40 of the trunk fiber 33 and advance an additional length of trunk fiber 33 from the spool to compensate for the decrease in length of the trunk fiber 33 caused by the cleaving. Of course, to facilitate this functionality, the trunk fiber 33 must be slidably disposed, and cannot be permanently affixed such as by an adhesive, within the pre-pent tip cannula 38. Using this technique, a trunk fiber 33 length of, for example, 10 to 12 feet can be maintained. Additionally, for sanitation purposes, the pre-bent tip cannula and any other appropriate components are typically sterilized, such as by autoclaving, on a regular and frequent basis.
FIG. 2 illustrates a plot of energy versus time for an output optical energy waveform 43 of a prior-art laser, such as the conventional laser assembly 25 depicted in FIG. 1. The output optical energy waveform 43 may be generated by a compact diode laser, such as a SIROlaser, manufactured by Sirona Dental Systems GmbH, of Germany, having a URL of www.sirona.com, operable at a wavelength of 980 nanometers and a repetition rate of about 10 kHz, and having an average power output, defined as the power delivered over a predetermined period of time, varying from 0.5 to 7 W. Each pulse of the depicted output optical energy waveform 43 has a pulse duration 46 and a pulse interval 48. In the illustrated example, the output optical energy waveform 43 can be generated such that the pulse duration 46 can have a value of about 50 microseconds and the pulse interval 48 can also have a value of about 50 microseconds. According to the exemplary depiction, the output optical energy waveform 43 can be said to have a pulse period 51 of about 100 microseconds, and, furthermore, the output optical energy waveform 43 can be said to have a pulse duty cycle, defined as the pulse duration 46 divided by the pulse interval 48, of about 50%. The pulse duration 46 and the pulse duration 48 of this exemplary prior-art system cannot be independently adjusted.
Another prior-art system is the LaserSmile™ laser, manufactured by BIOLASE Technology, Inc., of Irvine, Calif., having a URL of www.biolase.com. This laser can be operated at a wavelength of 810 nanometers and a repetition rate of, for example, about 0.01 to about 5 Hz, with corresponding pulse durations of about 0.02 to about 9.9 seconds, and with an average power output up to about 10 W. Output optical energy waveforms from the laser can have pulse duty cycles of, for example, between 10% and 50%. Additionally, while being independently adjustable, the pulse duration and pulse interval of the laser's output optical energy waveform tend to be relatively large and not adequately or optimally suited for a number of soft tissue cutting procedures, such as procedures designed to minimize an impartation of thermal energy into the target soft tissue.